This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Laughlin, R. C. Articles by Temesvari, L. A. Search for Related Content PubMed PubMed Citation Articles by Laughlin, R. C. Articles by Temesvari, L. A.

 Previous Article  |  Next Article 

Infection and Immunity, September 2004, p. 5349-5357, Vol. 72, No. 9
0019-9567/04/$08.00+0     DOI: 10.1128/IAI.72.9.5349-5357.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Involvement of Raft-Like Plasma Membrane Domains of Entamoeba histolytica in Pinocytosis and Adhesion

Richard C. Laughlin,¹ Glen C. McGugan,^2, Rhonda R. Powell,^2, Brenda H. Welter,^2, and Lesly A. Temesvari^2*

Department of Genetics and Biochemistry,¹ Department of Biological Sciences, Clemson University, Clemson, South Carolina²

Received 21 April 2004/ Accepted 22 May 2004

Lipid rafts are highly ordered, cholesterol-rich, and detergent-resistant microdomains found in the plasma membrane of many eukaryotic cells. These domains play important roles in endocytosis, secretion, and adhesion in a variety of cell types. The parasitic protozoan Entamoeba histolytica, the causative agent of amoebic dysentery, was determined to have raft-like plasma membrane domains by use of fluorescent lipid analogs that specifically partition into raft and nonraft regions of the membrane. Disruption of raft-like membrane domains in Entamoeba with the cholesterol-binding agents filipin and methyl-ß-cyclodextrin resulted in the inhibition of several important virulence functions, fluid-phase pinocytosis, and adhesion to host cell monolayers. However, disruption of raft-like domains did not inhibit constitutive secretion of cysteine proteases, another important virulence function of Entamoeba. Flotation of the cold Triton X-100-insoluble portion of membranes on sucrose gradients revealed that the heavy, intermediate, and light subunits of the galactose-N-acetylgalactosamine-inhibitible lectin, an important cell surface adhesion molecule of Entamoeba, were enriched in cholesterol-rich (raft-like) fractions, whereas EhCP5, another cell surface molecule, was not enriched in these fractions. The subunits of the lectin were also observed in high-density, actin-rich fractions of the sucrose gradient. Together, these data suggest that pinocytosis and adhesion are raft-dependent functions in this pathogen. This is the first report describing the existence and physiological relevance of raft-like membrane domains in E. histolytica.

Editor: W. A. Petri, Jr.

These authors contributed equally to this work.

This article has been cited by other articles:

• Bracha, R., Nuchamowitz, Y., Wender, N., Mirelman, D. (2007). Transcriptional Gene Silencing Reveals Two Distinct Groups of Entamoeba histolytica Gal/GalNAc-Lectin Light Subunits. Eukaryot Cell 6: 1758-1765 [Abstract] [Full Text]  
• Wender, N., Villalobo, E., Mirelman, D. (2007). EhLimA, a Novel LIM Protein, Localizes to the Plasma Membrane in Entamoeba histolytica. Eukaryot Cell 6: 1646-1655 [Abstract] [Full Text]  
• Leon-Sicairos, N., Reyes-Lopez, M., Canizalez-Roman, A., Bermudez-Cruz, R. M., Serrano-Luna, J., Arroyo, R., de la Garza, M. (2005). Human hololactoferrin: endocytosis and use as an iron source by the parasite Entamoeba histolytica. Microbiology 151: 3859-3871 [Abstract] [Full Text]  
• Beck, D. L., Boettner, D. R., Dragulev, B., Ready, K., Nozaki, T., Petri, W. A. Jr. (2005). Identification and Gene Expression Analysis of a Large Family of Transmembrane Kinases Related to the Gal/GalNAc Lectin in Entamoeba histolytica. Eukaryot Cell 4: 722-732 [Abstract] [Full Text]